Have you ever wanted to make all the cars just a little faster, turn better or brake harder? Usually that would require editing each car in the handling.dat. I got tired of that, so here's the solution. GTA IV HBE lets you change every car or every car of a specific type by a custom amount. For example, you can give all sports cars a 50% higher top speed in just a few seconds.
WARNING: This is not a beginner's tool, and you CAN mess up your handling.dat file. Always backup before playing around with it.
Requires .NET Framework 2.0 (and no, don't count on a newer version necessarily doing the trick)